Aberrant cell-restricted immunoglobulins provided with a toxic moiety

ABSTRACT

Described are immunoglobulins provided with a toxic moiety, comprising at least an immunoglobulin variable region that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells. These immunoglobulins provided with a toxic moiety are preferably used in selectively modulating biological processes. The provided immunoglobulins provided with a toxic moiety are of particular use in pharmaceutical compositions for the treatment of diseases related to cellular aberrancies, such as cancers and autoimmune diseases.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No. 13/739,974, filed Jan. 11, 2013, pending, which application claims the benefit under 35 U.S.C. §119(e) to U.S. Ser. No. 61/586,568, filed on Jan. 12, 2012, the disclosure of each of which is hereby incorporated herein in its entirety by this reference.

TECHNICAL FIELD

The disclosure relates to the field of biotechnology and biotherapeutics. More specifically, it relates to immunoglobulins provided with a toxic moiety and human antibodies. It also relates to the use of these biotherapeutics in the treatment of a host suffering from a disease associated with aberrant cells, such as cancers and autoimmune diseases.

BACKGROUND

The development of immunoglobulin-drug conjugates is a drug development field that receives great attention nowadays. Humanized or human antibodies are the largest and most important class of immunoglobulins under investigation for use in antibody-drug conjugates (ADCs) and in immunotoxins and antibody-radionuclide conjugates. These antibodies target binding sites (over)expressed at aberrant cells, such as those exposed in cancers and immune or autoimmune diseases, and during infections. Many of the conjugates have a limited degree of efficacy. For example, the maximum tolerated dose of immunotoxins is relatively low due to their toxicity towards healthy tissue. Lowering the dose is one way of protecting healthy cells for the non-specific toxic activity of the toxin or the drug in ADCs. Lowering the dose, however, hampers the delivery of an efficacious amount of conjugate at the site of for example a tumor. The unwanted side reactions are mainly due to the targeting of the antibodies to binding sites that are not exclusively exposed by aberrant cells but also to some extent by healthy cells. Thus, insufficient specificity for aberrant cells over healthy cells hampers desired efficacy and hampers obtaining the desired safety profiles of the nowadays immunoglobulin-drug conjugates.

Toxic moieties currently in the clinic or under investigation are numerous and Diverse.^([6]) Amongst the first toxins that were chemically linked to murine antibodies are plant-derived protein toxins and bacterial toxins such as saporin, Diphtheria toxin, Pseudomonas exotoxin, gelonin, ricin, ricin A chain, abrin and pokeweed antiviral protein. Other immunoglobulins provided with a toxin moiety comprise single chain Fv fused at the DNA level with toxins. An example is the recombinant protein BL22 consisting of the Fv portion of an anti-human CD22 antibody fused to a fragment of Pseudomonas exotoxin-A, that targets B-cell malignancies such as hairy cell leukemia and non-Hodgkin's lymphoma. Other examples of immunoglobulins conjugated to toxins are the antibody-radionuclide conjugates. Human CD20 has been chosen by drug developers as the target for two monoclonal antibodies, conjugated with 90-Yttrium or with 131-Iodine, for treatment of non-Hodgkin's lymphomas. In attempts to improve the tumor selectivity of certain drugs, murine monoclonal antibodies were conjugated to compounds such as doxorubicin, vinblastine, methotrexate, providing so-called antibody-drug conjugates. Insufficient tumor cell specificity however still limited the therapeutic usefulness. Even when selecting tumor cell surface antigens that are (highly) over-expressed at aberrant cells, still the low expression levels at healthy cells gives rise to insufficient selectivity of the antibody-drug conjugates. Current cytotoxic anti-tumor drugs under investigation are for example maytansinoids and dolastatin analogs, that both target intracellular tubulin, and duocarmycins and calicheamicins, which target DNA structure. These compounds are potent in their cytotoxic activity, though not selective for aberrant cells. Antibiotic calicheamicin conjugated to an anti-human CD33 monoclonal antibody was approved and used in the clinic, but was withdrawn due to serious side effects. Additional examples of drugs currently under investigation for their potential beneficial use in antibody-drug conjugates meant for the treatment of cellular aberrancies are ozogamicin, hydrazone-calicheamicin, vedotin, emtansine, mertansine. These toxic moieties are conjugated to immunoglobulins targeting cell surface markers expressed at tumor cells, though also expressed to some extent at healthy cells. Typical examples of immunoglobulin-drug conjugate-targeted cell surface markers present at both tumor cells and healthy cells are CD19, CD20, CD22, CD25, CD30, CD33, CD56, CD70, HER2/neu. All these immunoglobulin-drug conjugate development programs thus inherently bear the risk for unacceptable safety profiles and consequent poor efficacy due to low maximum tolerated doses. Conjugating drugs, radionuclides or toxins to immunoglobulins specifically and selectively targeting aberrant cells and not targeting healthy cells would thus provide for therapies with improved specificity and selectivity for aberrant cells and with an improved safety profile.

SUMMARY OF THE DISCLOSURE

Specific and selective delivery of a toxic moiety in target aberrant cells demands for binding molecules specific for binding sites preferentially associated with aberrant cells. These binding molecules then are used as carriers and transporters of the toxic moieties, specifically and selectively delivering the toxic moieties at and in the aberrant cells. Herein, we disclose immunoglobulin-drug conjugates comprising these preferred features. The immunoglobulins in the immunoglobulin-drug conjugates hereof comprise immunoglobulin binding regions with improved selectivity for aberrant cells by specifically binding to binding sites preferentially associated with these aberrant cells. We disclose as preferred targets for the antibody hereof, intracellular proteins that are associated with aberrant cells. These proteins are available as peptides presented by MHC on the surface of aberrant cells. The use of MHC-peptide complexes as targets opens us a new field of tumor targets, because so far typically targets associated with the surface of aberrant cells have been envisaged. Although it is preferred that the target is specific for aberrant cells (tumor cells) in many cases up-regulated intracellular proteins are also suitable for at least improving the therapeutic window of immunotoxins. Our most preferred targets are peptides derived from MAGE presented in the context of MHC-1. In particular MAGE peptides that are present in more than one MAGE protein (multi-MAGE epitope; see WO2012/091564 incorporated herein by reference). The toxic moiety for use herein is preferably a drug compound, a radionuclide or a toxin. A toxic moiety is a non-proteinaceous molecule or a proteinaceous molecule. In the immunoglobulin-drug conjugates hereof, the toxic moiety is preferably conjugated by chemical conjugation. Also preferred are immunoglobulins hereof fused at the DNA level to a proteinaceous toxic moiety.

The immunoglobulins in the immunoglobulin-drug conjugates hereof are suitable for the specific and selective localization of a toxic effect inside targeted aberrant cells, leaving healthy cells essentially unaffected. Immunoglobulins comprise immunoglobulin binding domains, referred to as immunoglobulin variable domains, comprising immunoglobulin variable regions. Maturation of immunoglobulin variable regions results in variable domains adapted for specific binding to a target binding site. Immunoglobulins are therefore particularly suitable for providing the immunoglobulin-drug conjugates hereof with the ability to specifically and selectively target aberrant cells. At their surface, aberrant cells present aberrant cell-associated antigen peptides in the context of major histocompatibility complex (MHC). Therefore, for the immunoglobulins in the immunoglobulin-drug conjugates hereof, aberrant cell-associated MHC-1 peptide complexes are a preferred target on aberrant cells. In addition, aberrant cell-associated MHC-2 peptide complexes are valuable targets on, e.g., tumors of hematopoietic origin, for the immunoglobulins in the immunoglobulin-drug conjugates hereof. Therefore provided are immunoglobulins in immunoglobulin-drug conjugates, with improved specificity and selectivity for aberrant cells by targeting MHC-peptide complexes which are preferentially associated with aberrant cells. This improved specificity and selectivity for aberrant cells is accompanied with a reduced level of unintentional targeting of healthy cells by the immunoglobulins in the immunoglobulin-drug conjugates hereof. Most preferably, healthy cells are not targeted by the immunoglobulin-drug conjugates hereof.

Thus, in a first embodiment the invention provides an immunoglobulin provided with a toxic moiety, comprising at least an immunoglobulin variable region that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells. Preferred immunoglobulins hereof are antibodies, but fragments and/or derivatives such as Fab and/or ScFv can also be used. Even more preferred immunoglobulins hereof are antibodies of the immunoglobulin G (IgG) type. Other immunoglobulins hereof are for example heavy-chain (only) antibodies comprising Vh or Vhh and IgA, and their fragments such as Fab fragments, and Fab fragments of IgGs. Immunoglobulins bind via their immunoglobulin variable regions to binding sites on molecules, such as epitopes, with a higher binding affinity than background interactions between molecules. In the context hereof, background interactions are typically interactions with an affinity lower than a K_(D) of 10E-4 M. Immunoglobulin variable domains in light chains (Vl) and immunoglobulin variable domains in heavy chains (Vh) of antibodies typically comprise the aberrant cell-specific immunoglobulin variable regions hereof.

Thus, in one embodiment, provided is an immunoglobulin provided with a toxic moiety, comprising at least an immunoglobulin variable region, wherein the immunoglobulin variable region is a Vh(h) that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells. Thus, in yet another embodiment, also provided is an immunoglobulin provided with a toxic moiety, comprising at least an immunoglobulin variable region, wherein the immunoglobulin variable region is a Vh that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells, and wherein the immunoglobulin variable region further comprises a Vl.

As said, immunoglobulins G are particularly suitable binding molecules for use in therapies specifically and selectively targeting aberrant cells, for site-specific delivery of a toxic moiety hereof Because the anticipated predominant use of the antibodies hereof is in therapeutic treatment regimes meant for the human body, in a particular embodiment hereof, the immunoglobulins provided with a toxic moiety have an amino-acid sequence of human origin. Thus, in one embodiment, provided is a human IgG provided with a toxic moiety, comprising at least an immunoglobulin variable region, wherein the immunoglobulin variable region is a Vh that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells, and wherein the immunoglobulin variable region further comprises a Vl. Of course, humanized antibodies, with the precursor antibodies encompassing amino acid sequences originating from other species than human, are also part hereof Also part hereof are chimeric antibodies, comprising (parts of) an immunoglobulin variable region hereof originating from a species other than human, and grafted onto a human antibody.

An aberrant cell is defined as a cell that deviates from its healthy normal counterparts. Aberrant cells are for example tumor cells, cells invaded by a pathogen such as a virus, and autoimmune cells.

Thus, in one embodiment, provided is an immunoglobulin according to any of the aforementioned embodiments wherein the MHC-peptide complex is specific for aberrant cells.

In the molecules hereof, the toxic moieties are preferably chemically linked to the immunoglobulins via any linker chemistry know in the art, and optionally via an additional spacer. Hereof, one or several, preferably two to six toxic moiety molecules are chemically linked to an immunoglobulin molecule hereof. The number of conjugated toxic moiety molecules per single immunoglobulin molecule is restricted by boundaries such as the number of available sites for conjugation on the immunoglobulin, the stability of the conjugate, the preservation of the ability of the immunoglobulin to specifically bind to an aberrant cell, etc. Of course, also two, three, etc., different toxic moieties can be linked to an immunoglobulin, depending amongst others on available binding sites and the applied linker chemistry. Chemical linking of the toxic moieties has several advantages when working with immunoglobulins. This way, toxic moieties cannot interfere with expression, folding, assembly and secretion of the immunoglobulin molecules.

Thus, in one embodiment, provided is an immunoglobulin according to any of the aforementioned embodiments wherein the toxic moiety is chemically linked to the immunoglobulin. It is then also part of the current invention that toxic moieties are covalently bound via peptide bonds, and preferably via a peptide linker, to the immunoglobulins hereof The toxic moiety and the immunoglobulin are then fused at the DNA level.

Thus, in one embodiment, provided is an immunoglobulin according to any of the aforementioned embodiments wherein the toxic moiety is a protein, preferably fused to the immunoglobulin at the DNA level, preferably through a linker sequence. In many instances, a simple Gly—Ser linker of 4-15 amino-acid residues may suffice, but if greater flexibility between the immunoglobulin and the toxic moiety is desired, longer or more complex linkers may be used. Preferred linkers are (Gly₄Ser)_(n) (SEQ ID NO:109), (GlySerThrSerGlySer)_(n) (SEQ ID NO:110), GlySerThrSerGlySerGlyLysProGlySerGlyGluGlySerThrLysGly (SEQ ID NO:105), GlyPheAlaLysThrThrAlaProSerValTyrProLeuAlaProValLeuGluSerSerGlySerGly (SEQ ID NO:111) or any other linker that provides flexibility allowing protein folding, stability against undesired proteolytic activity and flexibility for the immunoglobulins hereof to exert their activity.

Another group of preferred linkers are linkers based on hinge regions of immunoglobulins. These linkers tend to be quite flexible and quite resistant to proteases. The most preferred linkers based on hinge regions are GluProLysSerCysAspLysThrHisThr (linking Ch1 and Ch2 in IgG1) (SEQ ID NO:106), GluLeuLysThrProLeuGlyAspThrThrHisThr (IgG3) (SEQ ID NO:107), and GluSerLysTyrGlyProPro (IgG4) (SEQ ID NO:108). Thus, the role of any applied chemical linker in conjugates hereof or the role of any applied peptide linker in fused molecules hereof is aiding the dual activity of the antibodies hereof, i.e., specific and selective binding of the immunoglobulin to aberrant cells, and subsequent delivery of at least the toxic moiety in the targeted aberrant cells. Thus, in one embodiment, provided is the use of an immunoglobulin provided with a toxic moiety according to any of the aforementioned embodiments, for the treatment of a host suffering from a disease associated with aberrant cells. In a further embodiment, provided is the use of an immunoglobulin provided with a toxic moiety according to any of the aforementioned embodiments, for the treatment of a host suffering from a disease associated with aberrant cells wherein at least the toxic moiety is internalized into the aberrant cell. The immunoglobulins provided with a toxic moiety are for example used for the treatment of cancer. Thus, in one embodiment, provided is an immunoglobulin provided with a toxic moiety according to any of the aforementioned embodiments for use in the treatment of cancer.

Preferred toxic moieties are numerous. Several examples of preferred toxic moieties hereof are drugs such as doxorubicin, cisplatin, carboplatin, vinblastine, methotrexate, chelated radioactive metal ions, (synthetic) antineoplastic agents such as monomethyl auristatin E, radioactive iodine, radionuclides such as 90-Yttrium, 131-Iodine, to name a few, which are chemically conjugated to the immunoglobulins hereof. Also preferred toxic moieties are proteinaceous toxins such as a fragment of Pseudomonas exotoxin-A, statins, ricin A, gelonin, saporin, interleukin-2, interleukin-12, viral proteins E4 or f4, apoptin and NS1, and non-viral proteins HAMLET, TRAIL and mda-7. Thus, in one embodiment hereof, antibodies are provided for the specific targeting of aberrant cells, wherein the toxic moiety is selected from the list of available toxic moieties comprising toxins such as a fragment of Pseudomonas exotoxin-A, statins, chelated radioactive metal ions, radioactive iodine, ricin A, gelonin, saporin, interleukin-2, interleukin-12, radionuclides such as 90-Yttrium, 131-Iodine, drugs such as doxorubicin, taxol or derivatives, 5-FU, anthracyclines, vinca alkaloids, calicheamicins, cisplatin, carboplatin, vinblastine, methotrexate, (synthetic) antineoplastic agents such as monomethyl auristatin E, apoptin, parvovirus-H1 NS1 protein, E4 or f4, TRAIL, mda-7, HAMLET.

Proteinaceous molecules are molecules comprising at least a string of amino acid residues. In addition, hereof the proteinaceous molecules may comprise carbohydrates, disulphide bonds, phosphorylations, sulphatations, etc.

When antibodies hereof are designed to first bind to a target aberrant cell, followed by internalization, the toxic moiety can then subsequently have its intracellular (cytotoxic) function, i.e., inducing apoptosis.

For administration to subjects the antibodies hereof must be formulated. Typically these antibodies will be given parenterally. For formulation simply water (saline) for injection may suffice. For stability reasons more complex formulations may be necessary. The invention contemplates lyophilized compositions as well as liquid compositions, provided with the usual additives. Thus, in one embodiment, provided is a pharmaceutical composition comprising an immunoglobulin provided with a toxic moiety according to any of the aforementioned embodiments and suitable diluents and/or excipients.

The dosage of the antibodies hereof are established through animal studies, (cell-based) in vitro studies, and clinical studies in so-called rising-dose experiments. Typically, the doses will be comparable with present day antibody dosages (at the molar level). Typically, such dosages are 3-15 mg/kg body weight, or 25-1000 mg per dose.

In addition, especially in the more difficult to treat cellular aberrancies the first applications of the antibodies hereof will (at least initially) probably take place in combination with other treatments (standard care). Of course, also provided are antibodies for use in novel or first treatments of any malignancy accompanied by the occurrence of aberrant cells, for which current treatments are not efficient enough or for which currently no treatment options are available. Thus, for example, also provided is a pharmaceutical composition comprising an invented immunoglobulin provided with a toxic moiety and a conventional cytostatic and/or tumoricidal agent. Moreover, also provided is a pharmaceutical composition comprising an invented immunoglobulin provided with a toxic moiety for use in an adjuvant treatment of cancer. Thus, in one embodiment hereof, an invented immunoglobulin provided with a toxic moiety for use in an adjuvant treatment of cancer is provided. Additionally, also provided is a pharmaceutical composition comprising an invented immunoglobulin provided with a toxic moiety for use in a combination chemotherapy treatment of cancer. Examples of chemotherapeutical treatments that are combined with the pharmaceutical composition of the current invention are etoposide, paclitaxel, cisplatin, doxorubicin and methotrexate.

The pharmaceutical compositions hereof will typically find their use in the treatment of cancer, particularly in forms of cancer where the targets of the preferred antibodies hereof (complexes of MHC and tumor-specific antigen peptides) are presented by the tumors. Table 1, for example, gives a list of tumors on which complexes of MHC and MAGE-A peptides have been found. It is easy using an antibody hereof to identify tumors that present these target MHC-peptide complexes. This can be done in vitro or in vivo (imaging).

It is preferred that the cell-surface molecules comprising the binding sites for the antibodies hereof are internalized into the targeted aberrant cell, together with the antibodies hereof, or together with at least the toxic moiety of the antibodies hereof. In a particularly preferred embodiment hereof the targeted aberrant cells go into apoptosis as a result of the internalization. Thus, in one embodiment, provided is the use of an immunoglobulin provided with a toxic moiety according to any of the aforementioned embodiments, for the treatment of a host suffering from cancer, wherein at least the toxic moiety is internalized into the aberrant cell.

Also comprised herein is a nucleic acid molecule encoding the immunoglobulin part of an antibody according to any of the embodiments hereof, when the toxic moiety is chemically linked to the immunoglobulin in the antibody hereof. Thus, also comprised herein is a nucleic acid molecule encoding an immunoglobulin and a toxic moiety according to any of the embodiments hereof, when the toxic moiety is fused to the immunoglobulin at the DNA level. These molecules hereof can be produced in prokaryotes or eukaryotes. The codon usage of prokaryotes may be different from that in eukaryotes. The nucleic acids hereof can be adapted in these respects. Also, elements that are necessary for secretion may be added, as well as promoters, terminators, enhancers, etc. Also, elements that are necessary and/or beneficial for the isolation and/or purification of the immunoglobulins hereof or of the antibodies hereof may be added. Typically, the nucleic acids hereof are provided in an expression vector suitable for the host in which they are to be produced. Choice of a production platform will depend on the size of the molecule, the expected issues around protein folding, whether amino acid sequences are present in the immunoglobulin or in the antibody that require glycosylation, expected issues around isolation and/or purification, etc. For example, the presence of disulfide bonds in immunoglobulins or proteinaceous toxins hereof will typically guide the selection of the preferred production platform. Thus, typically nucleic acids hereof are adapted to the production and purification platform in which the immunoglobulins optionally with their fused proteinaceous toxins hereof are to be produced. Thus, provided is a vector comprising a nucleic acid molecule encoding an immunoglobulin or an antibody hereof For stable expression in a eukaryote it is preferred that the nucleic acid encoding the immunoglobulin or the antibody hereof is integrated in the host cell genome (at a suitable site that is not silenced). In one embodiment, also provided is a vector comprising means for integrating the nucleic acid in the genome of a host cell. The disclosure further comprises the host cell or the organism in which the nucleic acid molecule encoding for the immunoglobulin hereof optionally with their fused proteinaceous toxins, is present and which is thus capable of producing the immunoglobulin optionally with their fused proteinaceous toxins hereof. Thus, in a preferred embodiment, also provided is a cell comprising a nucleic acid molecule hereof, preferably integrated in its genome and/or a vector hereof, comprising a nucleic acid molecule encoding an immunoglobulin optionally with their fused proteinaceous toxins hereof.

Included herein invention is also a method for producing an immunoglobulin optionally with their fused proteinaceous toxins hereof, comprising culturing a cell hereof, comprising a nucleic acid molecule encoding an immunoglobulin optionally with their fused proteinaceous toxins hereof, preferably integrated in the cell's genome and/or a vector hereof, comprising a nucleic acid molecule encoding an immunoglobulin optionally with their fused proteinaceous toxins hereof, allowing for expression of the immunoglobulin optionally with their fused proteinaceous toxins and separating the immunoglobulin optionally with their fused proteinaceous toxins from the culture.

In one embodiment hereof, the immunoglobulin variable domains in the molecules hereof target one binding site. Also bi-specific immunoglobulins provided with a toxic moiety are provided that are specifically binding to two different binding sites associated with the cell surface of aberrant cells. By targeting with a single antibody hereof two different binding sites on an aberrant cell such as a tumor cell, the risk that both targets are also jointly present on a healthy cell is significantly further diminished. The affinity of the antibodies hereof for the two different target binding sites separately, preferably is designed such that K_(on) and K_(off) are very much skewed towards binding to both different binding sites simultaneously. Thus, the specificity of the bi-specific antibodies hereof is increased by increasing their specificity for binding to two different binding sites associated with aberrant cells. Thus, in one embodiment hereof, the antibody according to any of the previous embodiments is a hetero-dimeric bi-specific immunoglobulin G or heavy-chain only antibody comprising two different but complementary heavy chains. The two different but complementary heavy chains may then be dimerized through their respective Fc regions. Upon applying preferred pairing biochemistry, hetero-dimers are preferentially formed over homo-dimers. For example, two different but complementary heavy chains are subject to forced pairing upon applying the “knobs-into-holes” CH3 domain engineering technology as described (Ridgway et al., Protein Engineering, 1996 (ref. 14)). In a preferred embodiment hereof the two different immunoglobulin variable regions in the bi-specific immunoglobulins hereof specifically bind to an MHC-peptide complex preferentially associated with aberrant cells.

Typical preferred antibodies hereof are exemplified by the antibodies outlined in this section, in FIG. 5B, and by the examples provided below and in the Examples section. Thus the invention provides an immunoglobulin provided with a toxic moiety according to FIG. 5B.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1: Specific binding of HLA-A0201/multi-MAGE-A-specific phage clones isolated from a large human non-immune antibody Fab phage library. Individual antibody Fab expressing phages that were selected against biotinylated HLA-A0201/multi-MAGE-A were analyzed by ELISA for their capacity to bind the relevant peptide/MHC complex only. Streptavidin coated 96-well plates were incubated with soluble HLA-A0201/multi-MAGE-A (A2/multiMage) or HLA-A0201/JCV (A2/JC) peptide/MHC complexes (10 μg/ml, washed to remove non-bound complexes and incubated with individual phage clones. Non-binding phages were first removed by three washes with PBS/TWEEN®, followed by incubation with anti-M13 antibody (1 μg/ml, Amersham) for one hour by room temperature. Finally the wells were incubated with an HRP-labeled secondary antibody and bound phages detected.

FIG. 2: Phages AH5, CB1 and CG1 specifically bind cells presenting the multi-MAGE-Apeptide. Phages AH5, CB1, CG1, BD5 and BC7 that had shown specific binding in ELISA using the relevant HLA-A201/multi-MAGE-A complex and an irrelevant HLA-A201 complex loaded with a JCV peptide were analyzed for their capacity to bind cells presenting the multi-MAGE-A peptide in HLA-A0201 molecules. To this end, human B-LCL (BSM) were loaded with multi-MAGE-A peptide (10 μg in 100 μPBS) for 30 minutes at 37° C., followed by incubation with the Fab phages AH5, CB1, CG1, BD5 and BC7 and analyzed by flow-cytometry using anti-phage antibodies and a fluorescently labeled secondary antibody.

FIG. 3: Phages expressing HLA-A2/multi-MAGE-A-specific Fab bind tumor cells of distinct histologic origin. Phages AH5, CB1 and CG1 specific for HLA-A0201/multi-MAGE-A and a positive control phage specific for HA-0101/MAGE-A1 were used for staining of distinct tumor cell lines. To this end the prostate cancer cell line LNCaP, the multiple myeloma cell line MDN, the melanoma cell lines MZ2-MEL43 and G43, and the breast cancer cell line MDA-MD157 were incubated with the different phages (30 minutes at 4° C.), bound phages were then detected by flow cytometry using anti-phage antibodies and fluorescently labeled secondary antibodies.

FIG. 4: Phage AH5 specifically binds HLA-A0201/multi-MAGE-A complexes only. To determine specificity of the phage AH5 an ELISA was performed using relevant and irrelevant peptide/MHC complexes. HLA-A0201 with multi-MAGE-A, gp100, JCV and MAGE-C2 peptides, as well as HLA-A1 with MAGE-A1 peptide were coated on streptavidin 96-well plates and incubated with phage AH5.

FIG. 5: Cartoon displaying examples of preferred immunoglobulins provided with a toxic moiety, hereof.

Panel A: Cartoon displaying the topology of the twelve immunoglobulin domains assembled in an immunoglobulin G.

Panel B: Examples are provided of preferred immunoglobulins provided with a toxic moiety, hereof. Shown are immunoglobulins provided with a single toxic moiety such as for example a cytostatic agent, linked to the immunoglobulin with a chemical linker (exemplified by I. and II.; immunoglobulin-toxic moiety conjugates), or immunoglobulins provided with a single toxic moiety, linked to the immunoglobulin with a peptide linker (exemplified by III.; fused immunoglobulin-toxic moiety molecule). In IV., an immunoglobulin provided with a toxic moiety, hereof, is shown, comprising one immunoglobulin heavy chain comprising a fused proteinaceous toxic moiety, comprising immunoglobulin variable regions specific for a certain binding site, and comprising a second immunoglobulin heavy chain comprising immunoglobulin variable regions specific for a different binding site. Of course, also part hereof are bi-specific immunoglobulins provided with a toxic moiety, hereof, comprising two heavy chains comprising different immunoglobulin variable regions specific for different binding sites and further comprising the same or different proteinaceous toxic moieties fused two the heavy chains. Of course, as part hereof, more than one, and typically two to six toxic moiety molecules can be fused or conjugated to an immunoglobulin molecule.

FIG. 6: Human Fab phage F9 specifically binds HLA-A2/ FLWGPRALV (SEQ ID NO:23) positive CMT64 mouse lung tumor cells. Human Fab clone F9 was analyzed for its capacity to bind mouse lung tumor cells (CMT64) stably expressing the HLA-A2/FLWGPRALV (SEQ ID NO:23) complex. Purified Clone F9 Fab fragments (3 μg total) were incubated with 0.5×10⁶ CMT64 cells that do not express human HLA, that express HLA-A2/YLEYRQVPG (SEQ ID NO:3) or that express HLA-A2/FLWGPRALV (SEQ ID NO:23). After one hour incubation on ice CMT64 cells were incubated with a fluorescently labeled secondary antibody and analyzed by flow cytometry.

FIG. 7: Llama VHH specifically binds CMT64 mouse lung tumor cells expressing human HLA-A2/multi-MAGE-A. Llama VHH specific for A2/FLW or A2/YLE were analyzed by flow cytometry for their binding capacity to CMT64 cells expressing these human HLA-A0201/multi-MAGE-A complexes. Purified VHH fragments (3 μg total) were incubated with 0.5×10⁶ CMT64 cells, which do not express human HLA, that express HLA-A2/YLEYRQVPG (SEQ ID NO:3) or that express HLA-A2/FLWGPRALV (SEQ ID NO:23). After one hour incubation on ice CMT64 cells were incubated with a fluorescently labeled secondary antibody and analyzed by flow cytometry.

DETAILED DESCRIPTION

One aspect hereof relates to a method for providing the antibodies hereof. As described hereinabove, it typically involves providing a nucleic acid construct encoding the desired immunoglobulin part of antibodies hereof, or encoding the desired immunoglobulin fused to a proteinaceous toxic moiety. The nucleic acid construct can be introduced, preferably via a plasmid or expression vector, into a prokaryotic host cell and/or in a plant cell and/or in a eukaryotic host cell capable of expressing the construct. In one embodiment, a method hereof to provide an immunoglobulin or to provide an immunoglobulin fused to a proteinaceous toxic moiety comprises the steps of providing a host cell with the nucleic acid(s) encoding the immunoglobulin or the immunoglobulin fused to a proteinaceous toxic moiety, and allowing the expression of the nucleic acid(s) by the host cell.

It is part hereof that nucleic acids coding for selected (human) immunoglobulin Vh(h) domains according to any of the above embodiments are combined with nucleic acids coding for human immunoglobulin heavy chain constant domains, providing nucleic acid molecules hereof encoding for a heavy chain of a human antibody. The human antibody heavy chain protein product of such a nucleic acid molecule hereof, then may be hetero-dimerized with a universal human antibody light chain. It is also part hereof that nucleic acids coding for (jointly) selected human immunoglobulin Vl domains and Vh domains according to any of the above embodiments are combined with nucleic acids coding for a human immunoglobulin light chain constant domain and are combined with nucleic acids coding for human immunoglobulin heavy chain constant domains, respectively, providing nucleic acid molecules hereof encoding for a light chain and for a heavy chain of a human antibody. In yet another embodiment hereof, the nucleic acids coding for the complementarity determining regions 1, 2 and 3 (CDR1, CDR2, CDR3), forming together the immunoglobulin variable region of a selected immunoglobulin Vh domain and/or a selected immunoglobulin Vl domain according to any of the above embodiments are combined with nucleic acids coding for human immunoglobulin Vh domain frame work regions and/or human immunoglobulin Vl domain frame work regions, respectively, providing nucleic acid molecules hereof encoding for a heavy chain variable domain (Vh) of a human antibody and/or encoding for a light chain variable domain (Vl) of a human antibody (A method known in the art as “grafting”). These nucleic acid molecules encoding for variable domains Vh and/or Vl are, as part hereof, then combined with nucleic acids coding for human immunoglobulin constant domains, providing a nucleic acid molecule encoding for a human antibody heavy chain and/or providing a nucleic acid molecule encoding for a human antibody light chain.

Hereof, immunoglobulins or immunoglobulins fused to a proteinaceous toxic moiety are for example expressed in plant cells, eukaryotic cells or in prokaryotic cells. Non-limited examples of suitable expression systems are tobacco plants, Pichia pastoris, Saccharomyces cerevisiae. Also cell-free recombinant protein production platforms are suitable. Preferred host cells are bacteria, like for example bacterial strain BL21 or strain SE1, or mammalian host cells, more preferably human host cells. Suitable mammalian host cells include human embryonic kidney (HEK-293) cells, PERC6® cells or preferably Chinese hamster ovary (CHO) cells, which can be commercially obtained. Insect cells, such as S2 or S9 cells, may also be used using baculovirus or insect cell expression vectors, although they are less suitable when the immunoglobulins or the fused immunoglobulins-toxic moiety molecules hereof include elements that involve glycosylation. The produced immunoglobulins or fused immunoglobulin-toxic moiety molecules hereof can be extracted or isolated from the host cell or, if they are secreted, from the culture medium of the host cell. Thus, in one embodiment a method hereof comprises providing a host cell with one or more nucleic acid(s) encoding the immunoglobulin or the fused immunoglobulin-toxic moiety molecule, allowing the expression of the nucleic acids by the host cell. In another preferred embodiment a method hereof comprises providing a host cell with one or more nucleic acid(s) encoding two or more different immunoglobulins or two or more different fused immunoglobulin-toxic moiety molecules, allowing the expression of the nucleic acids by the host cell. For example, in one embodiment, nucleic acids encoding for a so-called universal immunoglobulin light chain and nucleic acids encoding for two or more different immunoglobulin heavy chains are provided, enabling isolation of mono-specific immunoglobulins or mono-specific fused immunoglobulin-toxic moiety molecules comprising homo-dimers of heavy chains and/or enabling isolation of bi-specific immunoglobulins or bi-specific fused immunoglobulin-toxic moiety molecules comprising hetero-dimers of heavy chains, with all different heavy chains complexed with a universal light chain. Methods for the recombinant expression of (mammalian) proteins in a (mammalian) host cell are well known in the art.

As said, it is preferred that the immunoglobulins hereof are linked with the toxic moieties via bonds and/or binding interactions other than peptide bonds. Methods for linking proteinaceous molecules such as immunoglobulins to other proteinaceous molecules or non-proteinaceous molecules are numerous and well known to those skilled in the art of protein linkage chemistry. Protein linkage chemistry not based on peptide bonds can be based on covalent interactions and/or on non-covalent interactions. A typical example of linkage chemistries applicable for linking toxic moieties to immunoglobulins hereof are the various applications of the Universal Linkage System disclosed in patent applications WO92/01699, WO96/35696, WO98/45304, WO03040722, the contents of each of which are incorporated herein by this reference.

As will be clear, an antibody hereof finds its use in many therapeutic applications and non-therapeutic applications, e.g., diagnostics, or scientific applications. Antibodies hereof, or more preferably the immunoglobulin part of the antibodies hereof, suitable for diagnostic purposes are of particular use for monitoring the expression levels of molecules exposing binding sites on aberrant cells that are targeted by antibodies hereof. In this way, it is monitored whether the therapy remains efficacious or whether other antibodies hereof targeting one or two different binding sites on the aberrant cells should be applied instead. This is beneficial when the expression levels of the first or the first two targeted binding site(s) are below a certain threshold, whereas another or new binding sites (still) can serve as newly targeted binding sites for antibodies hereof comprising the appropriate specific immunoglobulin variable regions for these alternative binding site(s). Antibodies hereof may also be used for the detection of (circulating) tumor cells, and for the target-cell specific delivery of immune-stimulatory molecules. For these later two uses, the sole immunoglobulins hereof without the fused or conjugated toxic moiety may also be used.

Provided herein is a method for inducing ex vivo or in vivo a modulating effect on a biological process in a target cell, comprising contacting the cell with an antibody hereof in an amount that is effective to induce the modulating effect. Preferably, the antibody hereof is used for a modulating effect on a biological process of aberrant cells in a subject, more preferably a human subject. For therapeutic applications in humans it is of course preferred that an antibody hereof does not contain amino acid sequences of non-human origin. More preferred are antibodies hereof, which only contain human amino acid sequences. Therefore, a therapeutically effective amount of an antibody hereof capable of recognizing and binding to one or two disease-specific binding sites and subsequently inducing a modulating effect on a biological process in the cell, can be administered to a patient to stimulate eradication of aberrant cells expressing the binding site(s) without affecting the viability of (normal) cells not expressing the disease-specific binding site(s). The specific killing of aberrant cells while minimizing or even avoiding the deterioration or even death of healthy cells will generally improve the therapeutic outcome of a patient after administration of the antibodies hereof.

Accordingly, also provided is the use of an antibody hereof as medicament. In another aspect, provided is the use of an antibody hereof for the manufacture of a medicament for the treatment of cancer, autoimmune disease, infection or any other disease of which the symptoms are reduced upon targeting aberrant cells expressing disease-specific binding sites with antibodies hereof. For example, an antibody hereof is advantageously used for the manufacture of a medicament for the treatment of various cancers (e.g., solid tumors, hematologic malignancies).

An example of a preferred antibody hereof is an antibody comprising at least an immunoglobulin variable region specifically binding to the complex between MHC-1 HLA-0201 and a multi-MAGE-A epitope, conjugated with a toxic moiety, using for example Universal Linkage System linker chemistry for conjugation. A second example of a preferred antibody hereof is an antibody comprising at least an immunoglobulin variable region specifically binding to the complex between MHC-1 HLA-CW7 and a multi-MAGE-A epitope, conjugated with a toxic moiety, using for example Universal Linkage System linker chemistry for conjugation. With the bi-specific antibodies hereof, difficult to target and/or difficult to reach aberrant cells have a higher chance of being “hit” by at least one of the two different immunoglobulin variable regions in the bi-specific antibodies hereof, thereby providing at least in part the therapeutic activity. An example of a preferred bi-specific antibody hereof is an immunoglobulin comprising an immunoglobulin variable region specific for the complex between MHC-1 HLA-0201 and a multi-MAGE-A epitope and comprising a second immunoglobulin variable region specific for the complex between MHC-1 HLA-CW7 and a second multi-MAGE-A epitope, conjugated with a toxic moiety.

Antibody fragments of human origin can be isolated from large antibody repertoires displayed by phages. One aspect hereof, known by the art, is the use of human antibody phage display libraries for the selection of human antibody fragments specific for a selected binding site, e.g., an epitope. Examples of such libraries are phage libraries comprising human Vh repertoires, human Vh-Vl repertoires, human Vh-Chl or human antibody Fab fragment repertoires.

Although the disclosure contemplates many different combinations of MHC and antigenic peptides the most preferred is the combination of MHC-1 and an antigenic peptide from a tumor related antigen presented by the MHC-1, exclusively expressed by aberrant cells and not by healthy cells. Because of HLA restrictions, there are many combinations of MHC-1-peptide complexes as well as of MHC-2-peptide complexes that can be designed based on the rules for presentation of peptides in MHC. These rules include size limits on peptides that can be presented in the context of MHC, restriction sites that need to be present for processing of the antigen in the cell, anchor sites that need to be present on the peptide to be presented, etc. The exact rules differ for the different HLA classes and for the different MHC classes. We have found that MAGE-derived peptides are very suitable for presentation in an MHC context. An MHC-1 presentable antigenic peptide with the sequence Y-L-E-Y-R-Q-V-P-G in MAGE-A (SEQ ID NO:3) was identified, that is present in almost every MAGE-A variant (multi MAGE peptide) and that will be presented by one of the most prevalent MHC-1 alleles in the Caucasian population (namely HLA-A0201). A second MAGE peptide that is presented by another MHC-1 allele (namely HLA-CW7) and that is present in many MAGE variants, like, for example, MAGE-A2, -A3, -A6 and -Al12, is E-G-D-C-A-P-E-E-K (SEQ ID NO:4). These two combinations of MHC-1 and MAGE peptides together would cover 80% of the Caucasian population. The same approach can be followed for other MHC molecules, other HLA restrictions and other antigenic peptides derived from tumor-associated antigens. Relevant is that the chosen antigenic peptide to elicit the response to must be presented in the context of an MHC molecule and recognized in that context only. Furthermore, the antigenic peptide must be derived from a sufficiently tumor-specific antigen and the HLA restriction must occur in a relevant part of the population. One of the important advantages of the invention is that tumors that down regulate their targeted MHC-peptide complex, can be treated with a second immunoglobulin comprising at least one variable region binding to a different MHC-peptide complex based on the same antigen. If this one is down regulated a third one will be available. For heterozygotes six different targets on MHC-1 may be available. Since cells need to be “inspected” by the immune system from time to time, escape through down regulation of all MHC molecules does not seem a viable escape route. In the case that MAGE is the antigen from which the peptide is derived escape through down regulation of the antigen is also not possible, because MAGE seems important for survival of the tumor.^([8])Thus the invention, in an important aspect reduces or even prevents escape of the tumor from the therapy. Thus, provided is in a preferred embodiment an antibody hereof whereby the immunoglobulin variable region is capable of binding to an MHC-I—peptide complex. In a further preferred embodiment the invention provides an immunoglobulin whereby the immunoglobulin variable region is capable of binding to MHC-I—peptide complexes comprising an antigenic peptide derived from a tumor related antigen, in particular MHC-I—peptide complexes comprising an antigenic peptide present in a variety of MAGE antigens, whereby the immunoglobulin is provided with a toxic moiety.

Because in one embodiment the invention uses MHC molecules as a target, and individuals differ in the availability of MHC targets, the invention also provides a so-called companion diagnostic to determine the HLA composition of an individual. Although the invention preferably uses a more or less universal (MAGE) peptide, the invention also provides a diagnostic for determining the expression of the particular antigen by the tumor. In this manner the therapy can be geared to the patient (personalized medicine, patient stratification), particularly also in the set-up to prevent escape as described herein before. It is known that the HLA restriction patterns of the Asian population and the black population are different from the Caucasian population. For different populations different MHC-peptide complexes can be targeted.

Although the present specification presents more specific disclosure on tumors, it must be understood that other aberrant cells can also be targeted by the antibodies of the invention. These other aberrant cells are typically cells that also proliferate without sufficient control. This occurs in autoimmune diseases. It is typical that these cells start to show expression of tumor antigens. In particular MAGE polypeptides have been identified in rheumatoid arthritis.^([7])

In literature, it is shown that a single nine amino-acid (A.A.) peptide present in MAGE-A2, -A3, -A4, -A6, -A10, and -Al2 is presented by HLA-A0201 on tumor cells, and can be recognized by cytotoxic T-lymphocytes.^([1 ]) This nine amino acid residues peptide with sequence Y-L-E-Y-R-Q-V-P-G (SEQ ID NO:3) is almost identical to the HLA-A0201 presented MAGE-A1 peptide Y-L-E-Y-R-Q-V-P-D (SEQ ID NO:5), except for the anchor residue at position 9. Replacement of the anchor residue with Valine results in a nine-amino-acid-residue peptide with enhanced binding capacity to HLA-A0201 molecules.^([1 ]) Human and mouse T-lymphocytes recognizing the Y-L-E-Y-R-Q-V-P-V (SEQ ID NO:6) peptide presented by HLA-0201 also recognize the original MAGE-A Y-L-E-Y-R-Q-V-P-G (SEQ ID NO:3) and Y-L-E-Y-R-Q-V-P-D (SEQ ID NO:5) peptides presented on tumors of distinct origin. As diverse tumors may each express at least one MAGE-A gene, targeting of this so-called multi-MAGE-A epitope includes the vast majority of tumors. As an example, MAGE-A expression in human prostate tumor cell lines and in human xenographs was analyzed and shown to be highly diverse, but in each individual sample tested at least one MAGE-A gene was expressed (Table 2), confirming that targeting this multi-MAGE-A epitope serves as a universal HLA-A0201 restricted target for therapy.

Of course several other multi-MAGE or multi-target epitopes may be designed. In principle the invention contemplates combinations of tumor-specific antigen-derived MHC presented epitopes in different HLA restrictions of both MHC-I and MHC-II, targeted by immunoglobulins linked to a toxic moiety, to induce apoptosis in aberrant cells. Examples of MHC-MAGE peptide combinations that can be targeted by antibodies hereof are peptide IMPKAGLLI (MAGE-A3) (SEQ ID NO:8) and HLA-DP4 or peptide 243-KKLLTQHFVQENYLEY-258 (MAGE-A3) (SEQ ID NO:9) and HLA-DQ6. Other non-limiting examples of tumor-specific complexes of HLA and antigen peptide are: HLA A1—MAGE-A1 peptide EADPTGHSY (SEQ ID NO:10), HLA A3—MAGE-A1 SLFRAVITK (SEQ ID NO:11), HLA A24—MAGE-A1 NYKHCFPEI (SEQ ID NO:12), HLA A28—MAGE-A1 EVYDGREHSA (SEQ ID NO:13), HLA B37—MAGE-A1/A2/A3/A6 REPVTKAEML (SEQ ID NO:14), expressed at aberrant cells related to melanoma, breast carcinoma, SCLC, sarcoma, NSCLC, colon carcinoma (N. Renkvist et al., Cancer Immunol. Immunother. (2001) V50:3-15 (ref. 13)). Further examples are HLA B53—MAGE-A1 DPARYEFLW (SEQ ID NO:15), HLA Cw2—MAGE-A1 SAFPTTINF (SEQ ID NO:16), HLA Cw3-MAGE-A1SAYGEPRKL (SEQ ID NO:17), HLA Cw16—MAGE-A1 SAYGEPRKL (SEQ ID NO:18), HLA A2—MAGE A2KMVELVHFL (SEQ ID NO:19), HLA A2—MAGE-A2 YLQLVFGIEV (SEQ ID NO:20), HLA A24—MAGE-A2 EYLQLVFGI (SEQ ID NO:21), HLA-A1—MAGE-A3 EADPIGHLY (SEQ ID NO:22), HLA A2—MAGE-A3 FLWGPRALV (SEQ ID NO:23), HLA B44—MAGE-A3 MEVDPIGHLY (SEQ ID NO:24), HLA B52—MAGE-A3 WQYFFPVIF (SEQ ID NO:25), HLA A2—MAGE-A4 GVYDGREHTV (SEQ ID NO:26), HLA A34—MAGE-A6 MVKISGGPR (SEQ ID NO:27), HLA A2—MAGE-A10 GLYDGMEHL (SEQ ID NO:28), HLA Cw7—MAGE-A12 VRIGHLYIL (SEQ ID NO:29), HLA Cw16—BAGE AARAVFLAL (SEQ ID NO:30), expressed by for example melanoma, bladder carcinoma, NSCLC, sarcoma, HLA A2—DAM-6/-10 FLWGPRAYA (SEQ ID NO:31), expressed by for example skin tumors, lung carcinoma, ovarian carcinoma, mammary carcinoma, HLA Cw6—GAGE-1/-2/-8 YRPRPRRY (SEQ ID NO:32), HLA A29—GAGE-3/-4/-5/-6/-7B YYWPRPRRY (SEQ ID NO:33), both expressed by for example melanoma, leukemia cells, bladder carcinoma, HLA B13 NA88-A MTQGQHFLQKV (SEQ ID NO:34), expressed by melanoma, HLA A2—NY-ESO-1 SLLMWITQCFL (SEQ ID NO:35), HLA A2—NY-ESO-la SLLMWITQC (SEQ ID NO:36), HLA A2—NY-ESO-1a QLSLLMWIT (SEQ ID NO:37), HLA A31NY-ESO-1a ASGPGGGAPR (SEQ ID NO:38), the latter four expressed by for example melanoma, sarcoma, B-lymphomas, prostate carcinoma, ovarian carcinoma, bladder carcinoma.

The disclosure is further described by the following non-limiting Examples.

Abbreviations used

A.A., amino acid; Ab, antibody; β2-M, CDR, complementarity determining region; CHO, Chinese hamster ovary; CT, cancer testis antigens; CTL, cytotoxic T-lymphocyte; E4orf4, adenovirus early region 4 open reading frame; EBV, Epstein-Barr virus; ELISA, enzyme linked immunosorbent assay; HAMLET, human αlactalbumin made lethal to tumor cells; HEK, human embryonic kidney; HLA, human leukocyte antigen; Ig, immunoglobulin; i.v., intravenously; kDa, kilo Dalton; MAGE, melanoma-associated antigen; Mda-7, melanoma differentiation-associated gene-7; MHC, major histocompatibility complex; MHC-p, MHC-peptide; NS1, parvovirus-H1-derived non-structural protein 1; PBSM, PBS containing 2% non-fat dry milk; TCR, T-cell receptor; VH, Vh or V_(H), amino-acid sequence of an immunoglobulin variable heavy domain; Vl, amino-acid sequence of an immunoglobulin variable light domain; TRAIL, tumor necrosis factor-related apoptosis-inducing ligand.

EXAMPLES Example 1

Non-exhaustive examples of immunoglobulins hereof comprising at least an immunoglobulin variable region that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells or to an aberrant cell surface marker preferentially associated with aberrant cells, with domain topologies as outlined for example in FIG. 5B, are:

Antibodies hereof comprising immunoglobulin variable regions that specifically bind to:

-   -   (a) a complex comprising a T-cell epitope selected from         146-KLQCVDLHV-154 (SEQ ID NO:74), 141-FLTPKKLQCV-150 (SEQ ID         NO:75), 154-VISNDVCAQV-163 (SEQ ID NO:76), 154-YISNDVCAQV-163         (SEQ ID NO:77) of PSA, presented by HLA-A2 and/or         162-QVHPQKVTK-170 (SEQ ID NO:78) of PSA, presented by HLA-A3,         and/or 152-CYASGWGSI-160 (SEQ ID NO:79), 248-HYRKWIKDTI-257 (SEQ         ID NO:80) of PSA, presented by HLA-A24, and/or 4-LLHETDSAV-12         (SEQ ID NO:81), 711-ALFDIESKV-719 (SEQ ID NO:82),         27-VLAGGFFLL-35 (SEQ ID NO:83) of PSMA, presented by HLA-A2,         and/or 178-NYARTEDFF-186 (SEQ ID NO:84), 227-LYSDPADYF-235 (SEQ         ID NO:85), 624-TYSVSFDSL-632 (SEQ ID NO:86) of PSMA, presented         by HLA-A24, and/or 299-ALDVYNGLL-307 (SEQ ID NO:87) of PAP,         presented by HLA-A2 and/or 213-LYCESVHNF-221 (SEQ ID NO:88) of         PAP, presented by HLA-A24 and/or 199-GQDLFGIWSKVYDPL-213 (SEQ ID         NO:89), 228-TEDTMTKLRELSELS-242 (SEQ ID NO:90) of PAP, presented         by MHC-2 and/or 14-ALQPGTALL-22 (SEQ ID NO:91),         105-AILALLPAL-113 (SEQ ID NO:92), 7-ALLMAGLAL-15 (SEQ ID NO:93),         21-LLCYSCKAQV-30 (SEQ ID NO:94) of PSCA, presented by HLA-A2         and/or 155-LLANGRMPTVLQCVN-169 (SEQ ID NO:95) of Kallikrein 4,         presented by DRB1*0404 and/or 160-RMPTVLQCVNVSVVS-174 (SEQ ID         NO:96) of Kallikrein 4, presented by DRB1*0701 and/or         125-SVSESDTIRSISIAS-139 (SEQ ID NO:97) of Kallikrein 4,         presented by DPB1*0401, for the treatment of prostate cancer;

(b) the HLA B8 restricted epitope from EBV nuclear antigen 3, FLRGRAYGL (SEQ ID NO:98), complexed with MHC I, for the clearance of EBV infected cells;

(c) the MAGE-A peptide YLEYRQVPG (SEQ ID NO:3) presented by MHC 1 HLA-A0201, for treatment of cancers accompanied by tumor cells expressing these MHC-peptide complexes (see Table 1);

(d) the MAGE-A peptide EGDCAPEEK (SEQ ID NO:4) presented by MHC-1 HLA-CW7, for treatment of cancers accompanied by tumor cells expressing these MHC-peptide complexes (see Table 1);

(e) complexes of HLA-A2 and HLA-A2 restricted CD8⁺T-cell epitopes, e.g., nonamer peptides FLFLLFFWL (SEQ ID NO:99) (from prostatic acid phosphatase (PAP, also prostatic-specific acid phosphatase (PSAP))), TLMSAMTNL (SEQ ID NO:100) (from PAP), ALDVYNGLL (SEQ ID NO:101) (from PAP), human HLA-A2.1-restricted CTL epitope ILLWQPIPV (SEQ ID NO:102) (from PAP-3), six-transmembrane epithelial antigen of prostate (STEAP), or complexes of HLA-A2.1 and HLA-A2.1-restricted CTL epitope LLLGTIHAL (SEQ ID NO:103) (from STEAP-3), epitopes from mucin (MUC-1 and MUC-2), MUC-1-32mer (CHGVTSAPDTRPAPGSTAPPAHGVTSAPDTRPA (SEQ ID NO:104)), epitopes from Globo H, Lewis^(y), Tn(c), TF(c) clusters, GM2, prostate-specific membrane antigen (PSMA), kallikrein 4, prostein, or complexes of HLA-A2.1 and HLA-A2.1-restricted epitopes from BA46, PTH-rP, HER-2/neu, hTERT, and MAGE-A8, for the treatment of prostate cancer;

(f) an aberrant cell-specific epitope in aberrant cell-specific altered MUC-1 complexed with MHC, or to an aberrant cell-specific epitope in aberrant cell-specific altered MUC-1 for, the targeting of aberrant cells in for example breast cancer or for the treatment of colorectal cancer;

(g) an aberrant cell-specific epitope of the aberrant cell-specific epidermal growth factor receptor mutant form vIII complexed with MHC, or to an aberrant cell-specific epitope of the epidermal growth factor receptor mutant form vIII, for the treatment of the brain neoplasm glioblastoma multiforme;

(h) the complex of MHC with T-cell epitope peptide 369-376 from human Her-2/neu, for the treatment of malignancies related to Her-2 and/or Her-1 over-expression;

(i) an epitope of the aberrant cell-specific surface marker CD44 splice variants known as CD44-v6, CD44-v9, CD44-v10, complexed with MHC, or to an aberrant cell-specific epitope of an aberrant cell-specific CD44 splice variant, for the treatment of multiple myeloma;

Target binding sites suitable for specific and selective targeting of infected aberrant cells by antibodies hereof are pathogen-derived antigen peptides complexed with MHC molecules. Examples of T-cell epitopes of the E6 and E7 protein of human papilloma virus, complexed with indicated HLA molecules, are provided below. Any combination of an HLA molecule complexed with a pathogen-derived T-cell epitope provides a specific target on infected aberrant cells for antibodies hereof. An example of an infected aberrant cell is a keratinocyte in the cervix infected by human papilloma virus (HPV), presenting T-cell epitopes derived from for example E6 or E7 protein, in the context of MHC. Examples of suitable target HPV 16 E6 T-cell epitopes are peptides FQDPQERPR (SEQ ID NO:39), TTLEQQYNK (SEQ ID NO:40), ISEYRHYCYS (SEQ ID NO:41) and GTTLEQQYNK (SEQ ID NO:42) binding to HLA A1, KISEYRHYC (SEQ ID NO:43) and YCYSIYGTTL (SEQ ID NO:44) binding to HLA A2, LLRREVYDF (SEQ ID NO:45) and IVYRDGNPY (SEQ ID NO:46) binding to HLA A3, TTLEQQYNK (SEQ ID NO:47) binding to HLA A11, CYSLYGTTL (SEQ ID NO:48), KLPQLCTEL (SEQ ID NO:49), HYCYSLYGT (SEQ ID NO:50), LYGTTLEQQY (SEQ ID

NO:51), EVYDFAFRDL (SEQ ID NO:52) and VYDFAFRDLC (SEQ ID NO:53) binding to HLA A24, 29-TIHDIILECV-38 (SEQ ID NO:54) binding to HLA A*0201. Equally suitable are HPV 16 E7 T-cell epitopes such as 86-TLGIVCPI-93 (SEQ ID NO:55), 82-LLMGTLGIV-90 (SEQ ID NO:56), 85-GTLGIVCPI-93 (SEQ ID NO:57) and 86-TLGIVCPIC-94 (SEQ ID NO:58) binding to HLA A*0201, HPV 18 E6 T-cell epitopes and HPV 18 E7 T-cell epitopes, binding to HLA A1, A2, A3, A11 or A24. Yet additional examples of T-cell epitopes related to HPV infected cells are HPV E7-derived peptides 1-MHGDTPTLHEYD-12 (SEQ ID NO:59), 48-DRAHYNIVTFCCKCD-62 (SEQ ID NO:60) and 62-DSTLRLCVQSTHVD-75 (SEQ ID NO:61) binding to HLA DR, 7-TLHEYMLDL-15 (SEQ ID NO:62), 11-YMLDLQPETT-20 (SEQ ID NO:63), 11-YMLDLQPET-19 (SEQ ID NO:64) and 12-MLDLQPETT-20 (SEQ ID NO:65) binding to HLA A*201, 16-QPETTDLYCY-25 (SEQ ID NO:66), 44-QAEPDRAHY-52 (SEQ ID NO:67) and 46-EPDRAHYNIV-55 (SEQ ID NO:68) binding to HLA B18, 35-EDEIDGPAGQAEPDRA-50 (SEQ ID NO:69) binding to HLA DQ2, 43-GQAEPDRAHYNIVTFCCKCDSTLRLCVQSTHVDIR-77 (SEQ ID NO:70) binding to HLA DR3, 50-AHYNIVTFCCKCD-62 (SEQ ID NO:71) binding to HLA DR15, 58-CCKCDSTLRLC-68 (SEQ ID NO:72) binding to HLA DR17 and 61-CDSTLRLCVQSTHVDIRTLE-80 (SEQ ID NO:73) binding to HLA-DRB1*0901.

A good source for selecting binding sites suitable for specific and selective targeting of aberrant cells by antibodies hereof, is the Peptide Database listing T-cell defined tumor antigens and the HLAs binding the T-cell epitopes^([9-12])(on the WorldWideWeb at cancerimmunity.org/peptidedatabase/Tcellepitopes.htm). The database provides combinations of antigen peptides complexed with MHC molecules comprising the indicated class of HLA, unique to tumor cells or over-expressed by tumor cells.

Example 2 Selection of Human Antibody Fragments Specific for HLA-A0201/Multi-MAGE-A.

To obtain human antibody fragments comprising immunoglobulin variable regions specific for the HLA-A0201 presented multi-MAGE-A epitope Y-L-E-Y-R-Q-V-P-V (SEQ ID NO:6) and FLWGPRALV (SEQ ID NO:23) a Human Fab phage display library was constructed according to the procedure previously described by de Haard et al.^([2]) and used for selections 1) essentially as described by Chames et al. using biotinylated MHC/p complexes,^([2] or) 2) on cells expressing the relevant antigen.

2.1: Selection of human antibody fragments specific for HLA-A0201/YLEYRQVPV (SEQ ID NO:6) using biotinylated MHC-peptide complexes:

Human Fab phages (10¹³ colony forming units) were first pre-incubated for one hour at room temperature in PBS containing 2% non-fat dry milk (PBSM). In parallel, 200 μl Streptavidin-coated beads (Dynal™) were equilibrated for one hour in PBSM. For subsequent rounds, 100 μl beads were used. To deplete for pan-MHC binders, each selection round, 200 nM of biotinylated MHC class I-peptide (MHC-p) complexes containing an irrelevant peptide (Sanquin, the Netherlands) were added to the phages and incubated for 30 minutes under rotation. Equilibrated beads were added, and the mixture was incubated for 15 minutes under rotation. Beads were drawn to the side of the tube using magnetic force. To the depleted phage fraction, subsequently decreasing amounts of biotinylated MHC-p complexes (200 nM for the first round, and 20 nM for the second and third round) were added and incubated for one hour at room temperature, with continuous rotation. Simultaneously, a pan-MHC class I binding soluble Fab (D3) was added to the phage-MHC-p complex mixture (50, 10, and 5 μg for rounds 1-3, respectively). Equilibrated streptavidin-coated beads were added, and the mixture was incubated for 15 minutes under rotation. Phages were selected by magnetic force. Non-bound phages were removed by five washing steps with PBSM, five steps with PBS containing 0.1% TWEEN®, and five steps with PBS. Phages were eluted from the beads by ten minutes incubation with 500 μl freshly prepared tri-ethylamine (100 mM). The pH of the solution was neutralized by the addition of 500 μl 1 M Tris (pH 7.5). The eluted phages were incubated with logarithmic growing E. Coli TG1 cells (OD₆₀₀nm of 0.5) for 30 minutes at 37° C. Bacteria were grown overnight on 2×TYAG plates. Next day, colonies were harvested, and a 10 0 inoculum was used in 50 ml 2x TYAG. Cells were grown until an _(OD600nm) of 0.5, and 5 ml of this suspension was infected with Ml3k07 helper phage (5 x 10¹¹ colony forming units). After 30 minutes incubation at 37° C., the cells were centrifuged, resuspended in 25 ml 2x TYAK, and grown overnight at 30° C. Phages were collected from the culture supernatant as described previously, and were used for the next round panning. After three selection rounds a 261-fold enrichment was obtained, and 46 out of 282 analyzed clones were shown to be specific for the HLA-A2-multi-MAGE-A complex (FIG. 1). ELISA using the HLA-A0201/multi-MAGE-A complexes as well as HLA-A0201 complexes with a peptide derived from JC virus was used to determine the specificity of the selected Fab.

2.2: Selection of human Fab specific for HLA-A0201/FLWGPRALV (SEQ ID NO:23) using cells.

Selections of Fab-phages specifically binding to HLA-A0201/FLWGPRALV (SEQ ID NO:23) were performed using mouse CMT64 lung tumor cells. To obtain CMT64 cells stably expressing HLA-A0201/FLWGPRALV (SEQ ID NO:23) (A2/FLW) complexes, the CMT64 cells were retroviral infected with a vector encoding a single chain peptide-β2M-HLA-A0201 heavy chain construct (SEQ ID NO:2). Human Fab phages (10¹³ colony forming units) were first pre-incubated for one hour at room temperature in PBS containing 2% FCS (PBSF). In parallel, 1.0×10⁶ CMT64-A2/FLW cells were equilibrated for one hour in PBSF. The phages were first incubated for one hour with 10×10⁶ CMT 64 cells expressing HLA-A0210/YLEYRQVPG (SEQ ID NO:3) to deplete non-specifically binding phages. The non-bound fraction was then incubated (one hour at 4° C.) with HLA-A0201/FLWGPRALV (SEQ ID NO:23) expressing CMT64 cells. After extensive washing, bound phages were eluted by adding 500 μl freshly prepared tri-ethylamine (100 mM). The pH of the solution was neutralized by the addition of 500 μl 1 M Tris (pH 7.5). The eluted phages were incubated with logarithmic growing E. Coli TG1 cells (OD_(600nm) of 0.5) for 30 minutes at 37° C. Bacteria were grown overnight on 2× TYAG plates. Next day, colonies were harvested. After four rounds of selection, individual clones were selected and tested for specificity of binding.

2.3: Human Fab specific for HLA-A0201/multi-MAGE-A epitopes bind antigen-positive cells.

Multi-MAGE-A;  Y-L-E-Y-R-Q-V-P-V

Fab phages were analyzed for their capacity to bind HLA-A0201-positive EBV-transformed B-LCL loaded with the multi-MAGE-A peptide Y-L-E-Y-R-Q-V-P-V (SEQ ID NO:6). The B-LCL line BSM (0.5×10⁶) was loaded with multi-MAGE-A peptide (10 μg in 100μl PBS) for 30 minutes at 37° C., followed by incubation with the Fab phages AH5, CB1, CG1, BD5 and BC7 and analyzed by flow-cytometry. As shown in FIG. 2, Fab AH5, CB1 and CG1, specifically bound to the peptide loaded cells only, whereas Fab BD5 and BC7 displayed non-specific binding to BSM that was not loaded with the multi-MAGE-A peptide. No binding was observed by AH5, CB1 and CG1 to non-peptide loaded cells.

Phages presenting AH5, CB1 and CG1, as well as the HLA-A0101/MAGE-A1-specific Fab phage G8 (4) were then used to stain tumor cell lines of distinct histologic origin. To this end prostate cancer cells (LNCaP), multiple myeloma cells (MDN), melanoma cells (MZ2-MEL43 and G43), and breast cancer cells (MDA-MB157) were stained and analyzed by flow cytometry (FIG. 3). The Fab AH5 specifically bound multiple myeloma cells MDN, and not the HLA-A0201-negative melanoma and breast cancer cells. Both CB1 and CG1 displayed non-specific binding on the melanoma cell line G43. The positive control Fab G8 demonstrated binding to all cell lines tested.

Multi-MAGE-A: (SEQ ID NO: 23) F-L-W-G-P-R-A-L-V 

To determine the cell-binding capacity of the HLA-A0201/FLWGPRALV (SEQ ID NO:23) selected Fab clone F9 soluble Fab fragments were made by induction of TG-1 bacteria. TG-1 containing pCes-F9 were grown until OD=0.8 and Fab production was induced by addition of 1 mM IPTG. After 13 hours induction the bacterial periplasmic fraction was isolated and dialyzed overnight. Next day soluble Fab F9 fragments were purified by IMAC.

Purified Fab F9 was added to 0.5×10⁶ CMT 64 cells expressing either HLA-A0210/YLEYRQVPG (SEQ ID NO:3), HLA-A0201/FLWGPRALV (SEQ ID NO:23), or CMT 64 cells that do not express human HLA. As shown in FIG. 6 the Fab clone F9 specifically binds HLA-A0201/FLWGPRALV (SEQ ID NO:23) expressing CMT64 cells and not CMT 64 cells that do not express human HLA or that do express the irrelevant HLA-A0201/YLEYRQVPG (SEQ ID NO:3) molecules.

2.4: Fab AH5 binds HLA-A0201/multi-MAGE-A complexes only.

ELISA using multiple peptide/MHC complexes then confirmed the specificity of Fab-AH5. To this end HLA-A0201 complexes presenting peptides multi-MAGE-A, gp100, JCV and MAGE-C2, as well as a HLA-A1/MAGE-A1 complex were immobilized on 96-well plates and incubated with phages displaying Fab AH5 and control Fab G8. As shown in FIG. 4, AH5 only binds HLA-A0201/multi-MAGE-A and not the irrelevant complexes HLA-A0201/gp100, HLA-A0201/MAGE-C2, HLA-A0201/JCV and HLA-A0101/MAGE-A1. The positive control Fab G8 only binds to its relevant target HLA-A0101/MAGE-A1.

The nucleic acids encoding for the HLA-A0201—multi-MAGE-A complex binding Fab AH5 will be combined with nucleic acids encoding for human antibody Ch2-Ch3 domains, providing nucleic acid molecules encoding for a human antibody light chain encompassing the selected Cl-Vl encoding nucleic acids and encoding for a human antibody heavy chain encompassing the selected Ch-Vh encoding nucleic acids. These nucleic acid molecules encoding the desired immunoglobulin will be introduced, via a plasmid or via an expression vector, into a eukaryotic host cell such as a CHO cell. After expression of the immunoglobulin, it will be isolated from the cell culture and purified. Then, a selected toxic moiety will be linked to the immunoglobulin, for example using Universal Linkage System linker chemistry.

Example 3 Cell Binding and Internalization of an Immunoglobulin Provided with a Toxic Moiety

Binding capacity of an antibody hereof is analyzed by flow-cytometry. For example, an antibody comprising immunoglobulin variable regions specific for complexes of HLA-A0201 and the multi-MAGE-A peptide is analyzed. HLA-A0201/multi-MAGE-A-positive tumor cells (Daju, MDN and mel 624) and HLA-A0201/multi-MAGE-A-negative cells (BSM, G43 and 293) are incubated on ice with purified antibody and detected by addition of fluorescently labeled antibodies. Cells bound by the antibody are quantified and visualized by flow-cytometry. Internalization of antibody is analyzed by confocal microscopy. To this end, cells are incubated with the antibody, kept on ice for 30 minutes to allow binding but no internalization. Next, fluorescently labeled antibodies specific for the antibody are added. To induce internalization cells are transferred to 37° C. and fixed with 1% PFA after 5, 10 and 15 minutes.

Example 4 Apoptosis Induction by Antibodies Hereof in Diverse Tumor Cells

4.1: Killing of diverse tumor cells by immunoglobulin provided with a toxic moiety.

Antibodies hereof are analyzed for their capacity to induce apoptosis by incubation with diverse tumor cells, known to express the antigens comprising the binding sites for the immunoglobulin variable regions. For example, an antibody comprising immunoglobulin variable region VH specific for complexes of HLA-A0201 and the multi-MAGE-A peptide, AH5-BTX, is coupled to a synthetic HPMA polymer containing the BTX peptide and Doxorubicin (as we described in WO2009131435, the contents of which are incorporated herein by this reference) and analyzed. To this end, antibodies hereof coupled to doxorubicin are analyzed for their capacity to induce apoptosis by incubation with diverse tumor cells known to express both HLA-A0201 and MAGE-A genes. The cell-lines Daju, Mel 624 (melanoma), PC346C (prostate cancer), and MDN (multiple myeloma) as well as MAGE-A-negative cells (911 and HEK293T) are incubated with different concentrations of the antibodies hereof (in DMEM medium, supplemented with pen/strep, Glutamine and non-essential amino acids). Several hours later, cells are visually inspected for classical signs of apoptosis such as detachment of the cells from tissue culture plates and membrane blebbing. In addition, cells are stained for active caspase-3 to demonstrate apoptosis. It is excepted that the antibodies hereof induce apoptosis in the Daju Mel 624, PC346C and MDN cells. Cells that are not treated with the antibodies hereof are not affected, as well as cells that do not express HLA-A0201 (HEK293T) and MAGE-A genes (911 and HEK293T).

Another antibody, comprising Vh and Vl domains (scFv) with specificity for complexes of HLA-A01, presenting a MAGE-A1 peptide was also analyzed. The scFv-BTX construct was coupled to the HPMA polymer containing doxorubicin and incubated with MAGE-A1-positive and MAGE-A1-negative cells. Apoptosis is shown by staining for active caspase-3.

4.2: Detection of Active Caspase-3

A classical intra-cellular hallmark for apoptosis is the presence of active caspase-3. To determine whether or not the antibodies hereof induce active caspase-3, Daju, Mel624 and MDN cells are incubated with various concentrations of antibodies hereof. After four and 13 hours FAM-DEVD-FMK, a fluorescently caspase-3/7 inhibitor, is added and positively stained cells are visualized by fluorescent microscopy and flow-cytometry. Caspase-3 activity is shown in antigen-positive cells and not in antigen-negative cells, with the (fragment of the) antigen providing the specific target-binding site for the antibodies hereof.

4.3: Treatment of Tumor Bearing Mice with Immunoglobulins Provided with a Toxic Moiety.

Nude mice (NOD-scid, eight per group) with a palpable subcutaneous transplantable human tumor (Daju or MDN) are injected with different doses of immunoglobulins provided with a toxic moiety. As a control mice are treated with standard chemotherapy or receive an injection with PBS. Mice receiving an optimal dose of the immunoglobulins provided with a toxic moiety survive significantly longer that those mice receiving chemotherapy or PBS, when the aberrant cells expose the target binding sites for the antibodies hereof.

Example 5

5.1: Selection of Llama VHH with Specificity for HLA-A0201/FLWGPRALV (SEQ ID NO:23) and HLA-A0201/YLEYRQVPG (SEQ ID NO:3)

Selection of Llama VHH fragments with specificity for HLA-A0201/FLWGPRALV (SEQ ID NO:23) (A2/FLW) and HLA-A0201/YLEYRQVPG (SEQ ID NO:3) (A2/YLE) were performed on CMT64 cells stably expressing these HLA/peptide complexes. Llama VHH phages (10¹¹ colony forming units) were first pre-incubated for one hour at room temperature in PBS containing 2% FCS (PBSF). In parallel, 1.0×10⁶ CMT64-A2/FLW and 1.0×10⁶ CMT64 A2/YLE cells were equilibrated for one hour in PBSF. To deplete for non-specific binding phages 10×10⁶ CMT 64 cells expressing either A2/FLW or A2/YLE were incubated for one hour with the llama VHH. The non-bound fractions were then incubated (one hour at 4° C.) with A2/FLW or A2/YLE expressing CMT64 cells. After extensive washing, bound phages were eluted by adding 500 μl freshly prepared tri-ethylamine (100 mM). The pH of the solution was neutralized by the addition of 500 μl 1 M Tris (pH 7.5). The eluted phages were incubated with logarithmic growing E. Coli TG1 cells (OD_(600nm) of 0.5) for 30 minutes at 37° C. Bacteria were grown overnight on 2× TYAG plates. Next day, colonies were harvested. After four rounds of selection individual clones were selected and tested for specificity of binding.

5.2: Llama VHH Specific for HLA-A0201/Multi-MAGE-A Epitopes Bind Antigen-Positive Cells

To determine the cell-binding capacity of the A2/FLW and A2/YLE selected VHH soluble VHH fragments were made by induction of TG-1 bacteria. TG-1 containing pHen-VHH were grown until OD=0.8 and Fab production was induced by addition of 1 mM IPTG. After 13 hours induction, the bacterial periplasmic fraction was isolated and dialyzed overnight. Next day, soluble VHH fragments were purified by IMAC.

CMT 64 cells (0.5×10⁶) expressing either HLA-A0210/YLEYRQVPG (SEQ ID NO:3), HLA-A0201/FLWGPRALV (SEQ ID NO:23), or CMT 64 cells that do not express human HLA were incubated with purified VHH fragments for one hour at 4° C. As shown in FIG. 7, the A2/FLW-specific VHH bind HLA-A0201/FLWGPRALV (SEQ ID NO:23) expressing CMT64 cells and not CMT 64 cells that do not express human HLA or that do express the irrelevant HLA-A0201/YLEYRQVPG (SEQ ID NO:3) molecules. The A2/YLE-specific VHH only bind HLA-A2/YLEYRQVPG (SEQ ID NO:3) expressing CMT64 cells and not A2/FLW-positive CMT64 cells and CMT64 cells that do not express human HLA.

References (the Contents of Each of which are Incorporated Herein by this Reference)

1. Graff-Dubois Stephanie, Olivier Faure, David-Alexandre Gross, Pedro Alves, Antonio Scardino, Salem Chouaib, Francois A. Lemonnier and Kostas Kosmatopoulos. Generation of CTL Recognizing an HLA-A*0201-Restricted Epitope Shared by MAGE-A1, -A2, -A3, -A4, -A6, -A10, and -A12 Tumor Antigens: Implication in a Broad-Spectrum Tumor Immunotherapy. The Journal of Immunology, 2002, 169:575-580.

2. de Haard Hans J., Nicole van Neer, Anneke Reurs, Simon E. Hufton, Rob C. Roovers, Paula Henderikx, Adriaan P. de Brume, Jan-Willem Arends, and Hennie R. Hoogenboom. A Large Non-immunized Human Fab Fragment Phage Library That Permits Rapid Isolation and Kinetic Analysis of High Affinity Antibodies. Journal of Biological Chemistry, 1999, 274: 18218-18230.

3. Chames P., H. R. Hoogenboom, and P. Henderikx. Selection of antigens against biotinylated antigens. In Antibody phage display, methods and protocols, Edited by P. M. O'Brien and R. Aitken. Methods in Molecular Biology 2002, 178:147-159.

4. Chames Patrick, Simon E. Hufton, Pierre G. Coulie, Barbara Uchanska-Ziegler, Hennie R. Hoogenboom. Direct selection of a human antibody fragment directed against the tumor T-cell epitope HLA-A1-MAGE-A1 from a nonimmunized phage-Fab library. PNAS, 2000, 97: 7969-7974.

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8. Marcar L., N. J. Maclaine, T. R. Hupp, and D. W. Meek. Mage-A cancer/testis antigens inhibit p53 function by blocking its interaction with chromatin. Cancer Res. 2010, 70:10362-10370.

9. Van den Eynde B. J., P. van der Bruggen. T cell-defined tumor antigens. Curr. Opin. Immunol. 1997, 9: 684-93.

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12. Parmiani G., A. De Filippo, L. Novellino, and C. Castelli. Unique human tumor antigens: immunobiology and use in clinical trials. J. Immunol. 2007, 178:1975-9.

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TABLE 1 Examples of the frequency of MAGE-A expression by human cancers. Frequency of expression (%) Cancer MAGE-A1 MAGE-A2 MAGE-A3 MAGE-A4 MAGE-A6 MAGE-A10 MAGE-A11 Melanoma 16 E 36 E 64 E 74 Head and neck 25 42 33  8 N N N Bladder 21 30 35 33 15 N  9 Breast  6 19 10 13  5 N N Colorectal N  5  5 N  5 N N Lung 21 30 46 11  8 N N Gastric 30 22 57 N N N N Ovarian 55 32 20 E 20 N N Osteosarcoma 62 75 62 12 62 N N hepatocarcinoma 68 30 68 N 30 30 30 Renal cell 22 16 76 30 N N N carcinoma E, expressed but the frequency is not known; N, expression by tumors has never been observed

TABLE 2 MAGE-A expression in human prostate cancer cell lines and prostate cancer xenografts. Cell line/ MAGE- Xenograft A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 LNCaP + ++ ++ ++ + PC346C + ++ ++ + ++ + + ++ OVCAR + + + + JON ++ ++ ++ + + PNT 2 C2 + + + + + SD48 + + + + PC-3 + + + PC 374 + PC 346p + ++ ++ ++ + ++ + PC 82 + + PC 133 ++ + + PC 135 + PC 295 + PC 324 + + + PC 310 + ++ + ++ + PC 339 ++ ++ + ++ + + + Expression of the MAGE-A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11 and A12 genes in diverse prostate tumor cell lines and prostate xenografts was analyzed by RT-PCR. Shown are expression levels in individual samples tested. Blank = no expression, + = low expression, ++ = high expression. All cell lines/xenografts express at least one MAGE-A gene.

SEQUENCE IDENTIFIERS

Amino acid sequence Vh AH5 SEQ ID NO: 1 QLQLQESGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKEREGVAVISYDGSNK YYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAGGSYYVPDYWGQGTLVTV SSGSTSGS. single chain HLA-A0201/FLWGPRALV construct. SEQ ID NO: 2 MAVMAPRTLVLLLSGALALTQTWAFLWGPRALVGGGGSGGGGSGGGGSGGGSGIQRT PKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDWSFYL LYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDMGGGGSGGGGSGGGGSGSHSMRY FFTSVSRPGRGEPRFIAVGYVDDTQFVRFDSDAASQRMEPRAPWIEQEGPEYWDGETRK VKAHSQTHRVDLGTLRGYYNQSESHTVQRMYGCDVGSDWRFLRGYHQYAYDGKDYI ALKEDLRSWTAADMAAQTTKHKWEAAHVAEQLRAYLEGTCVEWLRRYLENGKETLQ RTDSPKAHVTHHPRSKGEVTLRCWALGFYPADITLTWQLNGEELTQDMELVETRPAGD GTFQKWASVVVPLGKEQNYTCRVYHEGLPEPLTLRWEPPPSTDSYMVIVAVLGVLGAM AIIGAVVAFVMKRRRNTGGGDYALAPGSQSSEMSLRDCKA, Amino acid sequence MHC-1 HLA-A0201 presentable peptide in MAGE-A SEQ ID NO: 3 YLEYRQVPG. Amino acid sequence MHC-1 HLA-CW7 presentable peptide in MAGE-A SEQ ID NO: 4 EGDCAPEEK. Amino acid sequence MHC-1 HLA-A0201 presentable peptide in MAGE-A1 SEQ ID NO: 5 YLEYRQVPD. Amino acid sequence MHC-1 HLA-A0201 presentable peptide in MAGE-A1 with enhanced binding capacity for HLA-A0201 SEQ ID NO: 6 YLEYRQVPV. Amino acid sequence Vh binding domain 11H SEQ ID NO: 7 EVQLVQSGGGLVKPGGSLRLSCAASGFTFSDYYMSWIRQAPGKGLEWLSYISSDGSTIY YADSVKGRFTVSRDNAKNSLSLQMNSLRADDTAVYYCAVSPRGYYYYGLDLWGQGTT VTVSS. amino acid sequence of MAGE-A3 peptide epitope binding to HLA SEQ ID NO: 8 IMPKAGLLI, amino acid sequence of MAGE-A3 peptide epitope binding to HLA SEQ ID NO: 9 KKLLTQHFVQENYLEY, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 10 EADPTGHSY, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 11 SLFRAVITK, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 12 NYKHCFPEI, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 13 EVYDGREHSA, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 14 REPVTKAEML, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 15 DPARYEFLW, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 16 SAFPTTINF amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 17 SAYGEPRKL, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 18 SAYGEPRKL, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 19 KMVELVHFL, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 20 YLQLVFGIEV, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 21 EYLQLVFGI, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 22 EADPIGHLY, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 23 FLWGPRALV, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 24 MEVDPIGHLY, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 25 WQYFFPVIF, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 26 GVYDGREHTV, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 27 MVKISGGPR, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 28 GLYDGMEHL, amino acid sequence of MAGE peptide epitope binding to HLA SEQ ID NO: 29 VRIGHLYIL, amino acid sequence of BAGE peptide epitope binding to HLA SEQ ID NO: 30 AARAVFLAL, amino acid sequence of DAM-6 and DAM-10 peptide epitope binding to HLA SEQ ID NO: 31 FLWGPRAYA, amino acid sequence of GAGE-1/-2/-8 peptide epitope binding to HLA SEQ ID NO: 32 YRPRPRRY, amino acid sequence of GAGE-3/-4/-5/-6/-7B peptide epitope binding to HLA SEQ ID NO: 33 YYWPRPRRY, amino acid sequence of NA88-A peptide epitope binding to HLA SEQ ID NO: 34 MTQGQHFLQKV, amino acid sequence of NY-ESO-1 peptide epitope binding to HLA SEQ ID NO: 35 SLLMWITQCFL, amino acid sequence of NY-ESO-1a peptide epitope binding to HLA SEQ ID NO: 36 SLLMWITQC, amino acid sequence of NY-ESO-1a peptide epitope binding to HLA SEQ ID NO: 37 QLSLLMWIT, amino acid sequence of NY-ESO-1a peptide epitope binding to HLA SEQ ID NO: 38 ASGPGGGAPR, HPV 16 E6 T-cell epitope binding to HLA A1 SEQ ID NO: 39 FQDPQERPR, HPV 16 E6 T-cell epitope binding to HLA A1 SEQ ID NO: 40 TTLEQQYNK, HPV 16 E6 T-cell epitope binding to HLA A1 SEQ ID NO: 41 ISEYRHYCYS, HPV 16 E6 T-cell epitope binding to HLA A1 SEQ ID NO: 42 GTTLEQQYNK, HPV 16 E6 T-cell epitope binding to HLA A2 SEQ ID NO: 43 KISEYRHYC, HPV 16 E6 T-cell epitope binding to HLA A2 SEQ ID NO: 44 YCYSIYGTTL, HPV 16 E6 T-cell epitope binding to HLA A3 SEQ ID NO: 45 LLRREVYDF, HPV 16 E6 T-cell epitope binding to HLA A3 SEQ ID NO: 46 IVYRDGNPY, HPV 16 E6 T-cell epitope binding to HLA A11 SEQ ID NO: 47 TTLEQQYNK, HPV 16 E6 T-cell epitope binding to HLA A24 SEQ ID NO: 48 CYSLYGTTL, HPV 16 E6 T-cell epitope binding to HLA A24 SEQ ID NO: 49 KLPQLCTEL, HPV 16 E6 T-cell epitope binding to HLA A24 SEQ ID NO: 50 HYCYSLYGT, HPV 16 E6 T-cell epitope binding to HLA A24 SEQ ID NO: 51 LYGTTLEQQY, HPV 16 E6 T-cell epitope binding to HLA A24 SEQ ID NO: 52 EVYDFAFRDL, HPV 16 E6 T-cell epitope binding to HLA A24 SEQ ID NO: 53 VYDFAFRDLC, HPV 16 E6 T-cell epitope binding to HLA A*0201 SEQ ID NO: 54 29-TIHDIILECV-38, HPV 16 E7 T-cell epitope binding to HLA A*0201 SEQ ID NO: 55 86-TLGIVCPI-93, HPV 16 E7 T-cell epitope binding to HLA A*0201 SEQ ID NO: 56 82-LLMGTLGIV-90, HPV 16 E7 T-cell epitope binding to HLA A*0201 SEQ ID NO: 57 85-GTLGIVCPI-93, HPV 16 E7 T-cell epitope binding to HLA A*0201 SEQ ID NO: 58 86-TLGIVCPIC-94, HPV E7 T-cell epitope binding to HLA DR SEQ ID NO: 59 1-MHGDTPTLHEYD-12, HPV E7 T-cell epitope binding to HLA DR SEQ ID NO: 60 48-DRAHYNIVTFCCKCD-62, HPV E7 T-cell epitope binding to HLA DR SEQ ID NO: 61 62-DSTLRLCVQSTHVD-75, HPV E7 T-cell epitope binding to HLA A*201 SEQ ID NO: 62 7-TLHEYMLDL-15,   HPV E7 T-cell epitope binding to HLA A*201 SEQ ID NO: 63 11-YMLDLQPETT-20, HPV E7 T-cell epitope binding to HLA A*201 SEQ ID NO: 64 11-YMLDLQPET-19, HPV E7 T-cell epitope binding to HLA A*201 SEQ ID NO: 65 12-MLDLQPETT-20, HPV E7 T-cell epitope binding to HLA B18 SEQ ID NO: 66 16-QPETTDLYCY-25, HPV E7 T-cell epitope binding to HLA B18 SEQ ID NO: 67 44-QAEPDRAHY-52, HPV E7 T-cell epitope binding to HLA B18 SEQ ID NO: 68 46-EPDRAHYNIV-55, HPV E7 T-cell epitope binding to HLA DQ2 SEQ ID NO: 69 35-EDEIDGPAGQAEPDRA-50, HPV E7 T-cell epitope binding to HLA DR3 SEQ ID NO: 70 43-GQAEPDRAHYNIVTFCCKCDSTLRLCVQSTHVDIR-77, HPV E7 T-cell epitope binding to HLA DR15 SEQ ID NO: 71 50-AHYNIVTFCCKCD-62, HPV E7 T-cell epitope binding to HLA DR17 SEQ ID NO: 72 58-CCKCDSTLRLC-68, HPV E7 T-cell epitope binding to HLA-DRB1*0901 SEQ ID NO: 73 61-CDSTLRLCVQSTHVDIRTLE-80, PSA T-cell epitope binding to HLA-A2 SEQ ID NO: 74 146-KLQCVDLHV-154, PSA T-cell epitope binding to HLA-A2 SEQ ID NO: 75 141-FLTPKKLQCV-150, PSA T-cell epitope binding to HLA-A2 SEQ ID NO: 76 154-VISNDVCAQV-163, PSA T-cell epitope binding to HLA-A2 SEQ ID NO: 77 154-YISNDVCAQV-163, PSA T-cell epitope binding to HLA-A3 SEQ ID NO: 78 162-QVHPQKVTK-170, PSA T-cell epitope binding to HLA-A24 SEQ ID NO: 79 152-CYASGWGSI-160, PSA T-cell epitope binding to HLA-A24 SEQ ID NO: 80 248-HYRKWIKDTI-257, PSMA T-cell epitope binding to HLA-A2 SEQ ID NO: 81 4-LLHETDSAV-12, PSMA T-cell epitope binding to HLA-A2 SEQ ID NO: 82 711-ALFDIESKV-719, PSMA T-cell epitope binding to HLA-A2 SEQ ID NO: 83 27-VLAGGFFLL-35, PSMA T-cell epitope binding to HLA-A24 SEQ ID NO: 84 178-NYARTEDFF-186, PMSA T-cell epitope binding to HLA-A24 SEQ ID NO: 85 227-LYSDPADYF-235, T-cell epitope binding to HLA-A24 SEQ ID NO: 86 624-TYSVSFDSL-632, PAP T-cell epitope binding to HLA-A2 SEQ ID NO: 87 299-ALDVYNGLL-307, PAP T-cell epitope binding to HLA-A24 SEQ ID NO: 88 213-LYCESVHNF-221, PAP T-cell epitope binding to MHC-2 SEQ ID NO: 89 199-GQDLFGIWSKVYDPL-213, PAP T-cell epitope binding to MHC-2 SEQ ID NO: 90 228-TEDTMTKLRELSELS-242, PSCA T-cell epitope binding to HLA-A2 SEQ ID NO: 91 14-ALQPGTALL-22, PSCA T-cell epitope binding to HLA-A2 SEQ ID NO: 92 105-AILALLPAL-113, PSCA T-cell epitope binding to HLA-A2 SEQ ID NO: 93 7-ALLMAGLAL-15, PSCA T-cell epitope binding to HLA-A2 SEQ ID NO: 94 21-LLCYSCKAQV-30, Kallikrein 4 T-cell epitope binding to DRB1*0404 SEQ ID NO: 95 155-LLANGRMPTVLQCVN-169, Kallikrein 4 T-cell epitope binding to DRB1*0701  SEQ ID NO: 96 160-RMPTVLQCVNVSVVS-174, Kallikrein 4 T-cell epitope binding to DPB1*0401 SEQ ID NO: 97 125-SVSESDTIRSISIAS-139, EBV nuclear antigen 3 T-cell epitope binding to MHC I HLA B8 SEQ ID NO: 98 FLRGRAYGL, HLA-A2 restricted CD8⁺ T-cell epitope of PAP binding to HLA-A2 SEQ ID NO: 99 FLFLLFFWL, HLA-A2 restricted CD8⁺ T-cell epitope of PAP binding to HLA-A2 SEQ ID NO: 100 TLMSAMTNL, HLA-A2 restricted CD8⁺ T-cell epitope of PAP binding to HLA-A2 SEQ ID NO: 101 ALDVYNGLL, human HLA-A2.1-restricted CTL epitope of PAP-3 binding to HLA A2.1 SEQ ID NO: 102 ILLWQPIPV, HLA-A2.1-restricted CTL epitope of STEAP-3 binding to HLA-A2.1 SEQ ID NO: 103 LLLGTIHAL, HLA-A2.1-restricted CTL epitope of MUC-1 and MUC-2 binding to HLA-A2.1 SEQ ID NO: 104 CHGVTSAPDTRPAPGSTAPPAHGVTSAPDTRPA, (GlySerThrSerGlySer)n Ig linker SEQ ID NO: 105 GSTSGSGKPGSGEGASTKGGFAKTTAPSVYPLAPVLESSGSG, IgG1 Ch1-Ch2 hinge region linker SEQ ID NO: 106 EPKSCDKTHT, IgG3 hinge region linker SEQ ID NO: 107 ELKTPLGDTTHT, IgG4 hinge region linker SEQ ID NO: 108 ESKYGPP, 

1. An immunoglobulin provided with a toxic moiety, the immunoglobulin comprising at least an immunoglobulin variable region that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells.
 2. The immunoglobulin of claim 1, wherein the immunoglobulin variable region is a Vh or Vhh.
 3. The immunoglobulin of claim 2, wherein the immunoglobulin variable region further comprises a Vl.
 4. The immunoglobulin of claim 3, which is a human IgG.
 5. The immunoglobulin of claim 1, wherein the MHC-peptide complex is specific for aberrant cells.
 6. The immunoglobulin of claim 1, wherein the toxic moiety is chemically linked to the immunoglobulin.
 7. The immunoglobulin of claim 1, wherein the toxic moiety is a fusion protein, fused to the immunoglobulin at the DNA level.
 8. A pharmaceutical composition comprising the immunoglobulin of claim 1, and suitable diluents and/or excipients.
 9. A method of treatment of a host suffering from a disease associated with aberrant cells, comprising: utilizing the immunoglobulin of claim 1 to treat the host.
 10. The method according to claim 9, wherein the toxic moiety is internalized into an aberrant cell.
 11. The method according to claim 9 to treat cancer.
 12. The method according to claim 10 to treat cancer.
 13. An immunoglobulin provided with a toxic moiety according to FIG. 5, Panel B.
 14. The immunoglobulin of claim 1, wherein the MHC-peptide complex is specific for aberrant cells, through a peptide derived from MAGE.
 15. The immunoglobulin of claim 14, wherein the MHC-peptide complex is specific for aberrant cells, through a peptide derived from MAGE-A.
 16. The immunoglobulin of claim 7, wherein the fusion protein is fused to the immunoglobulin at the DNA level through a linking sequence.
 17. A human IgG immunoglobulin chemically linked to a toxic moiety, wherein the human IgG immunoglobulin comprises at least an immunoglobulin variable region that specifically binds to an MHC-peptide complex preferentially associated with aberrant cells, wherein the MHC-peptide complex is specific for aberrant cells through a peptide derived from MAGE-A, and wherein the toxic moiety is a fusion protein. 